Update on ACL Graft Selection Paul Marchetto, MD Associate - - PowerPoint PPT Presentation

Update on ACL Graft Selection

Paul Marchetto, MD

Associate Professor Orthopaedic Surgery Thomas Jefferson University Rothman Institute

ACL Graft Selection

 ACL reconstruction is the :

 6th most common procedure performed in

Orthopedic Surgery

 100,000 ACL reconstruction per year  85% of surgeons doing ACL surgery do <

10/yr

 Failure rate estimated at 10- 15%

ACL Graft Selection

 The ideal graft should

 Reproduce native anatomy and normal

biomechanics

 Rapidly incorporate with strong initial fixation  Low donor site morbidity  Limit risk of disease transmission  Allow for sufficient graft length and diameter  Be cost effective

ACL Graft Selection

 Important variables to consider in ACL

surgery

 Graft selection  Graft fixation  Tunnel placement  Functional rehabilitation

ACL Graft Selection

 Bone Patella Bone Autograft was considered the

“Gold Standard” for graft choice - this is rapidly changing

 With the evolution of ACL surgical technique and

improvements in technology, there is more variability in graft choice

 With no “Gold Standard” it is important when

choosing a graft, to understand the advantages and disadvantages of each.

ACL Graft Selection

 Autograft

 Bone - Patellar - tendon bone  Semitendinosis and Gracilis  Quadriceps tendon

ACL Graft Selection

 Allograft

 Bone patellar-tendon bone  Semitendinosis Gracilis  Achilles tendon  Quadriceps tendon

Criteria for ACL graft selection

 Biomechanics of normal ACL and ACL

Graft

 All current auto/allograft choices have higher

ultimate strength than native ACL

 Biological Healing

 BPTB autograft incorporate into bone tunnels

as early as 6 weeks

 Hamstring autograft – 12 weeks  Allograft as much as 6 months

Criteria for ACL graft selection

 Ease of harvest

 Operative time: BPTB auto is the most difficult  Hamstring is faster to harvest  There is a learning curve to all types of graft

harvesting with added potential for complications

 Return to play

 Surgeon dependent  Lack of objective evidence in decision criteria for

return to play

Criteria for ACL graft selection

 Donor site morbidity

 BPTB auto > QT auto > Hamstring auto

 Donor site complications

 Fracture of patella  Nerve injury with hamstring harvest  Anterior knee pain

Outline

 Graft Choices

 Autograft

• Patella Tendon
• Hamstring
• Quadriceps Tendon

 Allograft

• Patella Tendon
• Achilles Tendon
• Soft Tissue Allograft
• Tibialis
• Hamstring
• Sterilization

Biomechanical Properties

Graft Ultimate Strength (N) Stiffness (N/mm) Cross Sectional Area (mm2) Intact ACL 2160 242 44 BPTB (10 mm) 2977 620 50 QDHS 4590 861 53 Quad Tendon (10 mm) 2352 463 62 Anterior Tibial Tendon (single) 3412 344 38 Posterior Tibial Tendon (single) 3391 302 48

All grafts have higher strength & stiffness than native ACL

Grafts - Autograft

 Bone-patella tendon-bone

 Pros

• Most likely quickest healing
• Excellent fixation
• Good track record (results 90-

95%)

• Strength of graft

 Cons

• Linked to PF pain & DJD
• Risk of patella fracture
• Patella Tendon rupture
• Larger incision
• More painful surgery

Grafts - Autograft

 Hamstrings (Semitendinosis / Gracilis)

 Pros

• Strongest tensile strengths (>4000 N)
• Smaller incision
• Pediatric patient
• ? Hamstring regrowth

 Cons

• ? Fixation strength
• Residual muscle weakness
• Soft tissue to bone healing
• Harvest – possible short graft
• Graft size - diameter

Grafts - Autograft

 Quadriceps Tendon

 Pros

• Similar tensile strength to BPTB
• Fixation similar to BPTB
• Less anterior knee pain

Grafts - Autograft

 Quadriceps Tendon

 Cons

• Longer Incision
• Less experience
• Quad tendon weakness

Autograft Results

 BPTB vs. Hamstring

 No study to date demonstrated a superiority of any graft

source in stability and functional outcomes

 Morbidity of hamstring graft harvest is less than the morbidity of

bone-patella tendon-bone graft harvest

• Laxdal et al. (Arthroscopy ’06)
• Yasuda et al. (AJSM ‘95)

 Anterior knee pain, knee extension loss, kneeling pain & arthritis

statistically greater with the use of BPTB grafts compared to HS grafts

• Sajovic et al. (AJSM ’06)
• Kartus et al. (Arthroscopy ’01)

 Recent prospective 5 yr FU study of 2 equally matched groups:

statistically higher incidence of OA of the knee in patients BPTB graft (50%) compared to HS graft (17%)

• Sajovic et al. (AJSM ’06)

Autograft Results

 BPTB vs. Hamstring = Meta-analysis

 Yunes et al (Arthroscopy ’01) = 411 patients

• BPTB group had significant less laxity by KT-1000 than the

hamstring group

• BPTB = 18% higher rate of “return to preinjury level of activity”

 Freedman et al (AJSM ’03) = 1976 patients

• Increased PF pain, less laxity, lower rates of graft failure, improved

stability, and higher patient satisfaction in the BPTB group

 Prodromos et al (Arthroscopy ’05) = 56 studies

• HS group = higher stability depending on fixation type

 Goldblatt et al (Arthroscopy ’05) = 1039 patients

• Anterior knee pain, increased kneeling pain, flexion deficit with

BPTB autograft and extension deficit compared with HS autograft

• BPTB more likely to result in normal Lachman

exam, pivot shift exam, KT-1000 side-to-side difference <3mm, and fewer results with significant flexion loss

Autograft Results

 BPTB vs. Quad Tendon

 Staubli et al (AJSM ’99)

• BPTB > tensile strength

 Lee et al. (Arthroscopy ’04)

• Comparable results of BPTB vs. Quad

Autograft Results

 Comparison of all 3

 Joseph et al. (Orthopaedics ’06)

• Early comparison of 3 autografts
• Free quad tendon group achieved earlier full knee

extension

• Less pain with quad tendon
• Similar clinical results

Grafts - Allograft

 Public concern for disease transmission

Biomedical Tissue Services (BTS) 2008

 “Dentist Pleads Guilty to Stealing and

Selling Body Parts”

 Acquiring body parts from funeral homes

without proper screening and consent

Grafts - Allograft

 Disease transmission and infection  American Association of Tissue Banks

 AATB

AATB Screening guidelines

 Consent  History of donor

 Prior infections  Risk factors (homosexuality, sex for

money,illegal drug use, hemophilia)

 Physical Exam

 Needle wounds  Infection

AATB Screening guidelines

 Screening Tests on Blood and Tissue

 Donors must test negative for antibodies to (HIV)  Nucleic acid test (NAT) for HIV-1  Hepatitis B surface antigen  Antibody to hepatitis B core antigen  Antibodies to the hepatitis C virus (HCV)  Nucleic acid test (NAT) for HCV  Antibodies to T-lymphotropic virus, and syphilis

AATB Screening guidelines

 Nucleic acid testing for HIV and HCV  A new provision of the AATB as of March 9,

2005

 Nucleic acid testing markedly shortens the

window of time for the detection of the viruses.

AATB guidelines

 Tissue excisions must commence within 24

hours of asystole if the body was cooled

 Within 15 hours of death if the body was not

cooled

 An aseptic technique is used to retrieve all

tissues

 Tissues are cultured after harvest and prior to

processing

 All musculoskeletal tissues are processed in a

bacteriologically controlled and climate- controlled environment

Secondary Sterilization

 Eliminate all possibility of infection while

maintaining all biologic and mechanical properties of the tissue

 No technique currently exists that fulfills these

requirements

 Gamma irradiation is a popular method  2.5 megarads w/o significantly altering

biomechanical properties of graft

 Eliminating bacterial surface contamination

Grafts - Allograft

 The estimated risk for HIV transmission with a

connective tissue allograft is estimated to be 1:8,000,000

 CDC reported 26 cases of allografts associated

bacterial infections in an estimated 1 million musculoskeletal allograft

 The majority of infected grafts were from tissues

processed by the same tissue bank. This tissue bank was closed.

 All were processed aseptically  None were terminally sterilized

Allograft storage options

 Fresh Frozen allografts

 between temperatures of -80 to -196 degrees F  allows for storage of up to 3 to 5 years,  the process kills the cells.

 Cryopreservation

 tissue undergoes controlled-rate freezing  cellular water is extracted by glycerol and

dimethylsulfoxide.

 shelf life of 10 years and up to 80% of cells can

remain viable.

Allograft storage options

 Freeze drying or lyophilization

 Residual moisture level of <5%.  Stored at room temperature for up to 3 to 5

years.

 Requires rehydration

Grafts - Allograft

 Bone-patella tendon-bone

 Pros

• Bone – bone healing
• Graft size
• Fixation
• Incision size
• Shorter OR time
• Less post-op pain

 Cons

• Risk of infection
• Slower healing
• Cost
• Availability

Grafts - Allograft

 Achilles tendon

 Pros

• Bone – bone healing on femur
• Size of graft
• Ease of retroscrew fixation
• Smaller incision
• Shorter OR time
• Less post-op pain

 Cons

• Risk of infection
• Slower healing
• Cost
• Availability

Grafts - Allograft

 Soft tissue (hamstring / tibialis)

 Pros

• Graft strength
• Variability in size
• Smaller incisions
• Less post-op pain
• Shorter OR time

Grafts - Allograft

 Soft tissue (hamstring / tibialis)

 Cons

• Risk of infection
• Slower healing
• Cost
• Availability

Allograft Results

 Levitt et al (CORR ’94)

 BPTB / Achilles allograft

• 85% success, no difference in grafts

 Caborn et al (Arthroscopy ’02)

 Tibialis tendon

• No early failures and comparable results to auto

 Singal et al (Arthroscopy ’07)

 Tibialis tendon

• 23% ACL failures requiring revision

 Indelli et al (CORR ’04)

 Achilles tendon

• 92% returned to pre-injury activity level

Auto vs. Allo

 No level I randomized studies  BPTB

 Rihn et al (KSSTA ’06)

• No clinical difference between 2 groups

 Barrett et al (AJSM ’05)

• Older patients > 40
• Allo = quicker return to activity but increase laxity

 Shelton et al (Arthroscopy ’97)

• Similar results @ 2 & 5 years
• Allo = less incision pain / extention loss

 Harner et al (CORR ’96)

• No differences in outcome

Auto vs. Allo

 BPTB auto vs. Achilles allo

 Poehling et al (Arthroscopy ’05)

• Similar long-term results
• Less early pain and function limitation in allo

group  BPTB – Meta-analysis

 Krych et al (Arthroscopy ’08) = 534 patients

• NO DIFFERENCES when irradiated grafts were removed

from analysis  Meta-analysis

 Prodromos et al (KSSTA ’07)

• Allograft = 3x higher instability rates

Graft Summary

Graft Biologic Incorporation Initial Fixation Morbidity Ease of Harvest Versatility

Patella Tendon Auto

+ Bone Healing (6 weeks) + Interference screw

• Large

incision Debatable Single tunnel

• nly

Hamstring Auto

Tendon-bone healing (8-12 weeks) Variable + Smaller incision, less post-op pain Debatable Single & double tunnel

Allograft Soft Tissue

• Slower

Variable + None Less post-

• perative pain

+ The best! No incision Single & double tunnel

Quad Tendon Auto

+/- Bone & tendon healing Variable Possibly less than patellar tendon Debatable Single & possibly double tunnel

Return to Play

 Issue of return to play related to graft?  Prospective, randomized study of hamstring or

patellar tendon autograft

 Pre-injury return > BPTB  O’Neill et al

 Meta-analysis

 Return to pre-injury:  BPTB = 75%, HS = 64%  Yunes et al (Arthroscopy ’01)

 Return to play factors:

 School / graduation / timing of season  Family / work demands

Based on these Results

 My graft choice:

 Achilles Allograft  Hamstrings Autograft: Pediatric

patients, any patient opposed to allograft

 Soft tissue allograft: revisions,

multiligament reconstructions

 Fixation

 Bio absorbable interference

screws

THANK YOU